when drawing I prefer soundtracks over bands as I get distracted easily if background music has lyrics. Also, some of the bands I like tend to be too chaotic(i.e The Mars Volta, Meshuggah, King Crimson..)

I've noticed that movie soundtracks often create too strong images of the movie itself, so I started to collect playlist from game soundtracks that has the atmosphere I'm hoping to capture to the picture.
Sometimes it's just background ambient and it it works great.

Here's some soundtracks I've liked.

-The Witcher(game), some great tracks, I removed combat tracks from the playlist though.

-Severance: blade of darkness(game, also known as Blade: the edge of darkness) awesome soundtrack, Conan style! great game too

Neverwinter Nights(game) some good tracks.

Only movie soundtrack that I can think of right now is Bramstoker's Dracula(the one made in 90's), one of my fav. movie soundtracks.